1. Field of the Invention
The present invention relates to a radiation fin for radiating heat generated from a heating element, a cooling device equipped with a radiation fin, electronic equipment equipped with a cooling device, and a manufacturing method of a cooling device.
2. Description of Related Art
As a device for cooling a heating element, such as a central processing unit (CPU), there has heretofore been proposed a heat sink such as a radiation fin. In a heat sink, heat radiation thereof is hastened by air blown by a fan, for example.
This heat sink is constructed by stacking a plurality of fin members. Specifically, a claw portion and an engage hole are respectively disposed in the individual fins, and the heat sink is constructed by attaching plural fins to a fan case, or the like in the state in which the claw portions of the respective fins are engaged with the engage holes of the adjacent fins (for example, see a patent document 1: Japanese Laid-Open Patent No. 2002-314009).
However, for example, when a heat sink 205 described in the Patent Document 1 is attached to an air outlet 203a of a case 203 of a fan 210 as shown in FIG. 20, the following problems arise. For example, the flow of air generated by the rotation of an impeller 206 disposed in the fan case 203 has a certain angle to the longitudinal direction of the heat sink 205, and hence the air cannot flow through smoothly between the respective fins 202 of the heat sink 205. This causes not only a drop in a heat radiation efficiency, but also the drawback of becoming a noise source because the air is blown with the certain angle to the respective fins 202.
In addition, for example, to achieve that the flow of air generated by the impeller 206 can pass through smoothly between the respective fins 202, it is necessary to fix the heat sink 205 so as to be offset rightward when viewed, in the figure, from a rotation center P of the impeller 206 as shown in FIG. 21. This has the disadvantage that a cooling device itself becomes larger, and this is not fit for miniaturization.
To solve these problems, there is a cooling device in which the heat radiation is done by smoothly passing the air generated by a fan with the use of a heat sink 207 that is given a curvature after being constructed by stacking fins 208, as shown in FIG. 22. To curve the heat sink 207, however, equipment and a jig for making an angle are required, which causes a cost increase.